1. Field of the Invention
The present invention prelates to a multi-function peripheral device serving as a peripheral device of an information processing device and including a plurality of functions such as a scanner function, the multi-function peripheral device being capable of simultaneously executing the plurality of functions using multi-task processing. The present invention further relates to a recording medium storing a program for operating this multi-function peripheral device.
2. Description of the Related Art
Recently, development of multi-function peripheral devices has been proceeding at a startling rate. Such multi-function peripheral devices can serve as a peripheral device of an information processing device such as a personal computer. The multi-function peripheral devices include a plurality of functions such as a scanner function. The multi-function peripheral devices are capable of simultaneously executing the plurality of functions by using multi-task processing.
One such multi-function peripheral device includes a transmission/reception unit, such as an interface and a cable, for enabling transmission and reception of a variety of data, such as print data, scanner data, facsimile reception data, and facsimile transmission data, between the multi-function peripheral device and an information processing device, such as a personal computer. In this way the transmission/reception unit enables various functions of the multi-function peripheral device.
The transmission/reception unit has a buffer memory for temporarily storing a predetermined amount of data, such as one byte of data, from the information processing device. When the predetermined amount of data has been stored in the buffer memory, the transmission/reception unit transmits a signal for prohibiting the information processing device from transmission any further data. Also, the CPU of the multi-function peripheral device starts an interrupt routine to process the data received from the information processing device. Accordingly, the CPU of the multi-function peripheral device processes the data temporarily stored in the buffer memory and then immediately processes new data once it is transmitted from the information processing device and temporarily stored in the buffer memory.
However, the conventional multi-function peripheral device described above immediately processes data once data is received from the information processing device. Therefore, when the information processing device has an extrememly high processing capacity, and so transmits a great deal of data to the multi-function peripheral device in a short time, a great deal of the multi-function peripheral device""s capacity will be required to process data from the information processing device.
The multi-function peripheral device can also be provided with a transmission unit, such as a modem, for performing transmission or reception of data over a transmission line, such as a telephone line. When the transmission unit is transmitting or receiving while the transmission/reception unit receives data from the information processing device, then the CPU of the multi-function peripheral device can only allot an extremely short amount of processing time to process data transmitted or received via the transmission/reception unit, thereby causing problems in the transmission function.
For example, when the CPU of the information processing device has a higher capacity than the CPU of the multi-function peripheral device, then when a print task and a facsimile task are simultaneously performed, there is a possibility that the CPU of the information processing device will transmit print data to the multi-function peripheral device at a faster speed than the CPU of the multi-function peripheral device can process both the facsimile data and the print data. In this case, each time the CPU of the multi-function peripheral device transmits print data from the buffer memory of the transmission/reception unit, then new print data is immediately received from the information processing device and temporarily stored in the buffer memory of the transmission/reception unit. As a result, the CPU of the multi-function peripheral device will be constantly processing print data so that very little time is left for processing facsimile data. Proper processes become impossible to perform. Because the transmitting speed of the transmission unit can absolutely not be changed once set, if the CPU takes too much time to process data transmitted or received via the transmission/reception unit, then an error can result with the transmission function of the multi-function peripheral device. For example, transmission of response commands to a remote facsimile, transmission of facsimile data, or reception of facsimile data can require more than an allowable predetermined duration of time, so that a transmission error is generated in the multi-function peripheral device.
It is an objective of the present invention to overcome the above-described problems and to provide a multi-function peripheral device capable of performing continuous transmission of data over a transmission line without transmission of data being stopped because the CPU is presently processing data received from an information processing device.
A multi-function peripheral device according to the present invention serves as a peripheral device for an information processing unit and is capable of simultaneously executing a plurality functions by multi-task processing. In order to achieve the above-described objectives, the multi-function peripheral device according to the present invention includes: a transmission/reception unit that transmits and receives data, for performing a plurality of functions, between the multi-function peripheral device and the information processing device; a transmission unit that transmits and receives data to and from a remote transmission device via a transmission line; and a reception speed control unit that, when the transmission unit and the transmission/reception unit operate simultaneously, reduces reception speed at which the transmission/reception unit receives data from the information processing device.
With this configuration, the transmission/reception unit lowers the reception speed of data from the information processing device when the transmission unit and the transmission/reception unit are operated simultaneously. Therefore, a certain amount of time for processing data transmitted or received via the transmission unit will be secured so that transmission and reception of data over the transmission line can be smoothly continued without being stopped because data received from the information processing device is being processed. For example, when print data is being received from the information processing device simultaneously with transmission or reception of facsimile data over the transmission line, then the reception speed at which the print data is being received from the information processing device is lowered. Therefore, even if the information processing device has an extremely high processing capacity, both the print data and the facsimile data can be properly processed without transmission of the response commands through a remote device over the transmission circuit or without reception of the facsimile data exceeding an allowable predetermined duration of time. Therefore, no transmission errors will be generated.
The present invention can be applied to the multi-function peripheral device connected to a variety of different types of information processing device such as personal computers and workstations.
The plurality of functions including the scanner function can also include a printer function, a personal computer facsimile function, a copy function, and a facsimile function, although these are only possible examples. The personal computer facsimile function enables the multi-functional peripheral device to modulate image data from an information processing device and transmit the modulated image data over a transmission line, such as a telephone line. The personal computer facsimile function also enables the multi-function peripheral device to demodulate image data inputted over the transmission line and to supply the demodulated image data to the information processing device.
The transmission/reception unit can be a cable and an interface or some other types of transmission/reception unit such as a device for transmitting and receiving data using a wireless system.
An example of the transmission line is a telephone line. The telephone line can be a public telephone line or a dedicated line. The transmission line can be a line using actual cables and lines or can be a wireless system.
An example of a transmission unit is a facsimile machine, but could also be a personal computer capable of data transmission.
An example of a transmission speed control unit includes operations of the CPU based on a predetermined program.
According to another aspect of the present invention, the multi-function peripheral device further includes a transmission prohibition unit that prohibits the information processing device from transmitting data to the transmission/reception unit when the transmission/reception unit receives a predetermined amount of data from the information processing device. In this case, the reception speed control unit controls the transmission prohibition unit to prohibit the information processing device from transmitting data to the transmission/reception unit for a duration of time that is longer when the transmission unit and the transmission/reception unit operate simultaneously than when the transmission/reception unit do not operate simultaneously.
With this configuration, the transmission/reception unit lowers the reception speed of data from the information processing device by increasing duration of time at which reception of data is prohibited. In this way, the reception speed can be easily reduced.
In other words, reception of data from the information processing device is not only prohibited when data from the information processing device is temporarily stored in the buffer memory of the transmission/reception unit, but also prohibited for a predetermined duration of time after data is transmitted from the buffer memory so that the buffer memory is empty. Therefore, the multi-function peripheral device can process data from the information processing device during the prohibition period along with processing of data transmitted or received via the transmission unit.
The reception prohibition period is the period of time wherein both data from the information processing device and data received or transmitted via the transmission unit can be processed. It should be noted that when only the transmission/reception unit is operating, it is desirable that the reception prohibition period be set to as short a time period as possible so that the information processing device can be processed as quickly as possible.
According to another aspect of the present invention, the reception speed control unit controls the transmission prohibition unit to set the duration of time according to a transmission speed of the transmission unit.
With this configuration, reception speed of data from the transmission/reception unit is reduced in accordance with the transmission speed of the transmission unit while both the transmission unit and the transmission/reception unit are being operated simultaneously. Therefore, by setting the reception speed of data by the transmission/reception unit to a speed appropriate for transmission speed of the transmission unit, the reduction in reception speed can be kept to a minimum so that data from the information processing device can be efficiently processed.
According to another aspect of the present invention, a storage medium stores programs for controlling a multi-function peripheral device serving as a peripheral device for an information processing unit and capable of simultaneously executing a plurality functions by multi-task processing. In this case, the storage medium stores: a transmission/reception program that controls a transmission/reception unit to transmit and receive data, for performing a plurality of functions, between the multi-function peripheral device and the information processing device; a transmission program that controls a transmission unit to transmit and receive data to and from a remote transmission device via a transmission line; and a reception speed control program that, when the transmission unit and the transmission/reception unit operate simultaneously, controls to reduce reception speed at which the transmission/reception unit receives data from the information processing device.